Personal tools

Timing computations

From HaskellWiki

(Difference between revisions)
Jump to: navigation, search

Revision as of 12:34, 29 November 2006

Timing an IO computation.

import Text.Printf
import Control.Exception
import System.CPUTime
time :: IO t -> IO t
time a = do
    start <- getCPUTime
    v <- a
    end   <- getCPUTime
    let diff = (fromIntegral (end - start)) / (10^12)
    printf "Computation time: %0.3f sec\n" (diff :: Double)
    return v
main = do
    putStrLn "Starting..."
    time $ product [1..10000] `seq` return ()
    putStrLn "Done."

And running this.

$ runhaskell A.hs
Computation time: 1.141 sec

See also Timing out computations.